export class DHImporter {
    /**
     * Parse Adversary Text
     * @param {string} text
     * @returns {Array<Object>} Array of adversary data objects
     */
    static parseAdversaries(text) {
        const blocks = text.split(/^-----$/gm).filter(b => b.trim());
        const results = [];

        for (let block of blocks) {
            const lines = block.trim().split(/\r?\n/).map(l => l.trim()).filter(l => l);
            if (lines.length === 0) continue;

            try {
                const data = {
                    name: "Unknown Adversary",
                    type: "adversary",
                    img: "systems/daggerheart/assets/icons/documents/actors/dragon-head.svg",
                    prototypeToken: { texture: { src: "systems/daggerheart/assets/icons/documents/actors/dragon-head.svg" } },
                    system: {
                        tier: 1,
                        type: "standard",
                        resources: { hitPoints: { value: 0, max: 0 }, stress: { value: 0, max: 0 } },
                        damageThresholds: { major: 0, severe: 0 },
                        attack: {
                            name: "Attack",
                            type: "attack",
                            roll: { type: "attack", bonus: 0 },
                            damage: { parts: [] }
                        },
                        experiences: {},
                        motivesAndTactics: ""
                    },
                    items: []
                };

                let currentSection = "header";
                let featureBuffer = null;
                let lineIndex = 0;

                // --- Header Parsing ---
                // Name is line 0
                if (lines.length > 0) {
                    data.name = lines[0];
                    lineIndex = 1;
                }

                while (lineIndex < lines.length) {
                    let line = lines[lineIndex];

                    // --- Section Detection ---
                    if (line.match(/^Motives & Tactics[:]?$/i)) {
                        currentSection = "motives";
                        lineIndex++;
                        continue;
                    } else if (line.match(/^Features[:]?$/i)) {
                        currentSection = "features";
                        lineIndex++;
                        continue;
                    } else if (line.match(/^HP & Stress[:]?$/i)) {
                        currentSection = "hp_stress";
                        lineIndex++;
                        continue;
                    } else if (line.match(/^Experience[:]?$/i)) {
                        currentSection = "experience";
                        lineIndex++;
                        // Check if the rest of the line has content (old format)
                        const inlineExp = line.replace(/^Experience[:]?\s*/i, "");
                        if (inlineExp) {
                            DHImporter._parseExperienceLine(inlineExp, data);
                        }
                        continue;
                    }

                    // --- Section Processing ---

                    // HEADER / STATS (Before any specific section)
                    if (currentSection === "header") {
                        if (line.match(/Tier\s+(\d+)\s+(\w+)/i)) {
                            const match = line.match(/Tier\s+(\d+)\s+(\w+)/i);
                            data.system.tier = parseInt(match[1]);
                            data.system.type = match[2].toLowerCase();
                        }
                        else if (line.match(/^Difficulty:/i)) {
                            // Can be "Difficulty: 14" or "Difficulty: 11 | Thresholds: ..."
                            const valueMatch = line.match(/Difficulty:\s*(\d+)/i);
                            if (valueMatch) data.system.difficulty = parseInt(valueMatch[1]);

                            // Check for inline stuff (Old Format)
                            if (line.includes("|")) {
                                const parts = line.split("|").map(p => p.trim());
                                for (const part of parts) {
                                    if (part.startsWith("HP:")) {
                                        data.system.resources.hitPoints.max = parseInt(part.split(":")[1]);
                                    } else if (part.startsWith("Stress:")) {
                                        data.system.resources.stress.max = parseInt(part.split(":")[1]);
                                    } else if (part.startsWith("Thresholds:")) {
                                        const th = part.split(":")[1].split("/").map(t => parseInt(t.trim()));
                                        if (th[0]) data.system.damageThresholds.major = th[0];
                                        if (th[1]) data.system.damageThresholds.severe = th[1];
                                    }
                                }
                            }
                        }
                        else if (line.match(/^(Attack:|ATK:)/i)) {
                            // "Attack: +1" or "ATK: +2 | Claws: Melee | ..."
                            const bonusMatch = line.match(/(?:Attack|ATK):\s*([+-]?\d+)/i);
                            if (bonusMatch) data.system.attack.roll.bonus = parseInt(bonusMatch[1]);

                            // If split format e.g. "Attack: +1" and next line is "Claws: Melee..."
                            if (!line.includes("|") && lineIndex + 1 < lines.length) {
                                const nextLine = lines[lineIndex + 1];
                                if (nextLine.includes(":") && !nextLine.match(/^(Experience|Features|Motives|Difficulty)/)) {
                                    // Likely the weapon details: "Claws: Melee | 1d8+3 phy"
                                    DHImporter._parseAttackDetails(nextLine, data);
                                    lineIndex++; // Consume next line
                                }
                            } else if (line.includes("|")) {
                                // Inline formatting
                                const parts = line.split("|").slice(1).join("|"); // remove ATK part
                                DHImporter._parseAttackDetails(parts, data);
                            }
                        }
                        else if (line.match(/^Experience:/i)) {
                            // Handled by section detection usually, but if missed:
                            const inlineExp = line.replace(/^Experience:\s*/i, "");
                            if (inlineExp && inlineExp.trim() !== "—") {
                                DHImporter._parseExperienceLine(inlineExp, data);
                            }
                            // If empty, next lines will be picked up by 'experience' section logic if we switched?
                            // Actually, if we are here, we might have skipped section detect if regex didn't match perfectly.
                        }
                        else {
                            // Description text usually
                            if (!data.system.notes) data.system.notes = "";
                            data.system.notes += line + "<br>";
                        }
                    }

                    // MOTIVES
                    else if (currentSection === "motives") {
                        data.system.motivesAndTactics += line + " ";
                    }

                    // EXPERIENCE (Multi-line)
                    else if (currentSection === "experience") {
                        // "Ambusher +3"
                        DHImporter._parseExperienceLine(line, data);
                    }

                    // HP & STRESS (Vertical)
                    else if (currentSection === "hp_stress") {
                        // Heuristic parsing for the copy-paste mess
                        // Look for numbers that might be thresholds
                        if (line.match(/^\d+$/)) {
                            const val = parseInt(line);
                            // Context matters. 
                            // If previous line was "minor" or "1 HP" (implied minor), val is minor.
                            // If previous line was "HP:" or "STRESS:", val is that.

                            const prevLine = lines[lineIndex - 1] || "";
                            const prevPrevLine = lines[lineIndex - 2] || "";

                            if (prevLine.match(/HP:/i)) {
                                data.system.resources.hitPoints.max = val;
                            } else if (prevLine.match(/STRESS:/i)) {
                                data.system.resources.stress.max = val;
                            } else if (prevLine.includes("minor") || prevPrevLine.includes("minor")) {
                                data.system.damageThresholds.minor = val;
                            } else if (prevLine.includes("major") || prevPrevLine.includes("major")) {
                                data.system.damageThresholds.major = val;
                            } else if (prevLine.includes("severe") || prevPrevLine.includes("severe")) {
                                data.system.damageThresholds.severe = val;
                            } else if (prevLine.includes("HP")) {
                                if (prevPrevLine.includes("minor")) { /* ignore or store */ }
                                if (prevPrevLine.includes("major")) data.system.damageThresholds.major = val;
                                if (prevPrevLine.includes("severe")) data.system.damageThresholds.severe = val;
                            }
                        }
                    }

                    // FEATURES
                    else if (currentSection === "features") {
                        const featureMatch = line.match(/^(.+?)\s+[–-]\s+(\w+)(?::\s*(.*))?$/);
                        // "Name - Type" (Description on next line) OR "Name - Type: Description"

                        if (featureMatch) {
                            if (featureBuffer) data.items.push(DHImporter._createFeatureItem(featureBuffer));
                            featureBuffer = {
                                name: featureMatch[1].trim(),
                                typeHint: featureMatch[2].trim(),
                                description: featureMatch[3] || ""
                            };
                        } else if (featureBuffer) {
                            featureBuffer.description += (featureBuffer.description ? " " : "") + line;
                        }
                    }

                    lineIndex++;
                }

                // Flush feature
                if (featureBuffer) data.items.push(DHImporter._createFeatureItem(featureBuffer));

                results.push(data);
            } catch (e) {
                console.error("Failed to parse adversary block", e, block);
            }
        }
        return results;
    }

    static _parseAttackDetails(line, data) {
        // Claws: Melee | 1d8+3 phy OR Claws: Melee 1d8+3 phy
        // Simple heuristic splitting
        let parts = line.split("|").map(p => p.trim());
        if (parts.length === 1) {
            // Try splitting by : for name/range
            const firstColon = line.indexOf(":");
            if (firstColon > -1) {
                const name = line.substring(0, firstColon).trim();
                const rest = line.substring(firstColon + 1).trim();
                const rangeMatch = rest.match(/^(\w+)\s+(.*)$/);
                if (rangeMatch) {
                    parts = [name + ":" + rangeMatch[1], rangeMatch[2]];
                } else {
                    parts = [line];
                }
            }
        }

        // Now parse parts roughly matching old logic
        // Part 0: Name: Range
        if (parts.length > 0) {
            const nameRange = parts[0].split(":");
            data.system.attack.name = nameRange[0].trim();
            if (nameRange[1]) data.system.attack.range = nameRange[1].trim().toLowerCase();
        }
        // Part 1: Damage
        if (parts.length > 1) {
            const dmgStr = parts[1];
            const dmgMatch = dmgStr.match(/^(.+?)\s+(\w+)$/);
            let formula = dmgStr;
            let type = "physical";
            if (dmgMatch) {
                formula = dmgMatch[1];
                type = dmgMatch[2].toLowerCase();

                // Map short codes
                if (type === "phy") type = "physical";
                else if (type === "mag") type = "magic";
            }
            data.system.attack.damage.parts.push({
                type: [type],
                applyTo: "hitPoints",
                value: {
                    custom: { enabled: true, formula: formula },
                    multiplier: "flat", dice: "d6"
                }
            });
        }
    }

    static _parseExperienceLine(line, data) {
        // "Ambusher +3"
        const match = line.match(/(.+?)\s+([+-]?\d+)$/);
        if (match) {
            const currentCount = Object.keys(data.system.experiences).length;
            const key = "exp" + currentCount;
            data.system.experiences[key] = {
                name: match[1].trim(),
                value: parseInt(match[2])
            };
        }
    }

    /**
     * Helper to create feature item data
     */
    static _createFeatureItem(buffer) {
        // In the future, we could map "Action" vs "Passive" to system fields if available.
        // For now, Daggerheart features are mostly just text descriptions, 
        // sometimes with specific actions embedded.
        // We will put the type in the description.

        const isAction = buffer.typeHint?.toLowerCase() === "action";

        const item = {
            name: buffer.name,
            type: "feature",
            img: "icons/svg/item-bag.svg",
            system: {
                description: `<p><strong>${buffer.typeHint}</strong>: ${buffer.description}</p>`,
                actions: {}
            }
        };

        if (isAction) {
            const actionId = foundry.utils.randomID();
            item.system.actions[actionId] = {
                _id: actionId,
                type: "attack",
                name: buffer.name,
                actionType: "action",
                img: "icons/svg/item-bag.svg",
                systemPath: "actions",
                chatDisplay: true
            };
        }

        return item;
    }

    /**
     * Parse Environment Text
     * @param {string} text
     * @returns {Array<Object>}
     */
    static parseEnvironments(text) {
        const blocks = text.split(/^-----$/gm).filter(b => b.trim());
        const results = [];

        for (let block of blocks) {
            const lines = block.trim().split(/\r?\n/).map(l => l.trim()).filter(l => l);
            if (lines.length === 0) continue;

            try {
                const data = {
                    name: lines[0],
                    type: "environment",
                    img: "systems/daggerheart/assets/icons/documents/actors/forest.svg",
                    system: {
                        tier: 1,
                        type: "exploration",
                        difficulty: 12,
                        impulses: "",
                        potentialAdversaries: { label: "" },
                        notes: ""
                    },
                    items: []
                };

                let lineIndex = 1;
                // Tier 1 Exploration
                if (lineIndex < lines.length) {
                    const tierMatch = lines[lineIndex].match(/Tier\s+(\d+)\s+(\w+)/i);
                    if (tierMatch) {
                        data.system.tier = parseInt(tierMatch[1]);
                        data.system.type = tierMatch[2].toLowerCase();
                        lineIndex++;
                    }
                }

                // Description
                let description = [];
                while (lineIndex < lines.length) {
                    const line = lines[lineIndex];
                    if (line.match(/^(Impulses|Difficulty|Potential Adversaries|Features)/i)) {
                        break;
                    }
                    description.push(line);
                    lineIndex++;
                }
                data.system.notes = description.join("<br>");

                let currentSection = "header";
                let featureBuffer = null;

                while (lineIndex < lines.length) {
                    const line = lines[lineIndex];
                    if (line.match(/^Impulses:/i)) {
                        data.system.impulses = line.replace(/^Impulses:\s*/i, "").trim();
                    } else if (line.match(/^Difficulty:/i)) {
                        data.system.difficulty = parseInt(line.split(":")[1].trim());
                    } else if (line.match(/^Potential Adversaries:/i)) {
                        data.system.potentialAdversaries.label = line.replace(/^Potential Adversaries:\s*/i, "").trim();
                    } else if (line.match(/^Features/i)) {
                        currentSection = "features";
                    } else if (currentSection === "features") {
                        // Parsing Features: "Name - Type: Description"
                        const featureMatch = line.match(/^(.+?)\s+[–-]\s+(\w+):\s*(.*)/);
                        if (featureMatch) {
                            if (featureBuffer) {
                                data.items.push(DHImporter._createFeatureItem(featureBuffer));
                            }
                            featureBuffer = {
                                name: featureMatch[1],
                                typeHint: featureMatch[2],
                                description: featureMatch[3]
                            };
                        } else if (featureBuffer) {
                            featureBuffer.description += "<br>" + line;
                        }
                    }
                    lineIndex++;
                }
                if (featureBuffer) {
                    data.items.push(DHImporter._createFeatureItem(featureBuffer));
                }
                results.push(data);

            } catch (e) {
                console.error("Failed to parse environment block", e);
            }
        }
        return results;
    }

    static async checkExistingFeatures(dataList) {
        if (!dataList || dataList.length === 0) return dataList;

        const results = [];
        // Pre-fetch world packs content index for speed, or just search relevant packs
        // For simplicity, we search all packs
        const packs = game.packs.filter(p => p.documentName === "Item");

        for (const actorData of dataList) {
            const enrichedActor = { ...actorData, foundFeatures: {} };

            for (const item of actorData.items) {
                if (item.type !== "feature") continue;

                // Search for item by name
                let found = null;
                for (const pack of packs) {
                    const index = pack.index.size > 0 ? pack.index : await pack.getIndex();
                    const entry = index.find(i => i.name === item.name);
                    if (entry) {
                        found = {
                            uuid: entry.uuid,
                            name: entry.name,
                            pack: pack.metadata.label
                        };
                        break;
                    }
                }

                if (found) {
                    enrichedActor.foundFeatures[item.name] = found;
                }
            }
            results.push(enrichedActor);
        }
        return results;
    }

    static async createDocuments(dataList, type) {
        if (!dataList || dataList.length === 0) return;

        const Actor = getDocumentClass("Actor");
        const actorsToCreate = [];

        for (const data of dataList) {
            // Process Items based on 'useCompendium' flags or similar set by the UI
            // The UI should have modified data.items or we loop through and replace based on user choice
            const finalItems = [];
            for (const item of data.items) {
                if (data.useFeatures && data.useFeatures[item.name]) {
                    // User selected to use existing feature
                    const uuid = data.useFeatures[item.name];
                    const original = await fromUuid(uuid);
                    if (original) {
                        finalItems.push(original.toObject());
                    } else {
                        finalItems.push(item);
                    }
                } else {
                    finalItems.push(item);
                }
            }
            data.items = finalItems;

            // Clean up temporary flags
            delete data.foundFeatures;
            delete data.useFeatures;

            actorsToCreate.push(data);
        }

        await Actor.createDocuments(actorsToCreate);
    }
}