/**
 * Phase Router — create, list, get, update, dependencies, bulk create
 */

import { TRPCError } from '@trpc/server';
import { z } from 'zod';
import { simpleGit } from 'simple-git';
import type { Phase } from '../../db/schema.js';
import type { ProcedureBuilder } from '../trpc.js';
import { requirePhaseRepository, requireTaskRepository, requireBranchManager, requireInitiativeRepository, requireProjectRepository, requireExecutionOrchestrator, requireReviewCommentRepository, requireChangeSetRepository } from './_helpers.js';
import { phaseBranchName } from '../../git/branch-naming.js';
import { ensureProjectClone } from '../../git/project-clones.js';
import type { FileStatEntry } from '../../git/types.js';
import { phaseMetaCache, fileDiffCache } from '../../review/diff-cache.js';

export function phaseProcedures(publicProcedure: ProcedureBuilder) {
  return {
    createPhase: publicProcedure
      .input(z.object({
        initiativeId: z.string().min(1),
        name: z.string().min(1),
      }))
      .mutation(async ({ ctx, input }) => {
        const repo = requirePhaseRepository(ctx);
        return repo.create({
          initiativeId: input.initiativeId,
          name: input.name,
          status: 'pending',
        });
      }),

    listPhases: publicProcedure
      .input(z.object({ initiativeId: z.string().min(1) }))
      .query(async ({ ctx, input }) => {
        const repo = requirePhaseRepository(ctx);
        return repo.findByInitiativeId(input.initiativeId);
      }),

    getPhase: publicProcedure
      .input(z.object({ id: z.string().min(1) }))
      .query(async ({ ctx, input }) => {
        const repo = requirePhaseRepository(ctx);
        const phase = await repo.findById(input.id);
        if (!phase) {
          throw new TRPCError({
            code: 'NOT_FOUND',
            message: `Phase '${input.id}' not found`,
          });
        }
        return phase;
      }),

    updatePhase: publicProcedure
      .input(z.object({
        id: z.string().min(1),
        name: z.string().min(1).optional(),
        content: z.string().nullable().optional(),
        status: z.enum(['pending', 'approved', 'in_progress', 'completed', 'blocked', 'pending_review']).optional(),
      }))
      .mutation(async ({ ctx, input }) => {
        const repo = requirePhaseRepository(ctx);
        const { id, ...data } = input;
        return repo.update(id, data);
      }),

    approvePhase: publicProcedure
      .input(z.object({ phaseId: z.string().min(1) }))
      .mutation(async ({ ctx, input }) => {
        const repo = requirePhaseRepository(ctx);
        const taskRepo = requireTaskRepository(ctx);

        const phase = await repo.findById(input.phaseId);
        if (!phase) {
          throw new TRPCError({
            code: 'NOT_FOUND',
            message: `Phase '${input.phaseId}' not found`,
          });
        }
        if (phase.status !== 'pending') {
          throw new TRPCError({
            code: 'BAD_REQUEST',
            message: `Phase must be pending to approve (current status: ${phase.status})`,
          });
        }

        // Validate phase has work tasks (filter out detail tasks)
        const phaseTasks = await taskRepo.findByPhaseId(input.phaseId);
        const workTasks = phaseTasks.filter((t) => t.category !== 'detail');
        if (workTasks.length === 0) {
          throw new TRPCError({
            code: 'BAD_REQUEST',
            message: 'Phase must have tasks before it can be approved',
          });
        }

        return repo.update(input.phaseId, { status: 'approved' });
      }),

    deletePhase: publicProcedure
      .input(z.object({ id: z.string().min(1) }))
      .mutation(async ({ ctx, input }) => {
        const repo = requirePhaseRepository(ctx);
        await repo.delete(input.id);

        // Reconcile any applied changesets that created this phase.
        // If all created phases in a changeset are now deleted, mark it reverted.
        if (ctx.changeSetRepository) {
          try {
            const csRepo = requireChangeSetRepository(ctx);
            const affectedChangeSets = await csRepo.findAppliedByCreatedEntity('phase', input.id);
            for (const cs of affectedChangeSets) {
              const createdPhaseIds = cs.entries
                .filter(e => e.entityType === 'phase' && e.action === 'create')
                .map(e => e.entityId);
              const survivingPhases = await Promise.all(
                createdPhaseIds.map(id => repo.findById(id)),
              );
              if (survivingPhases.every(p => p === null)) {
                await csRepo.markReverted(cs.id);
              }
            }
          } catch {
            // Best-effort reconciliation — don't fail the delete
          }
        }

        return { success: true };
      }),

    createPhasesFromPlan: publicProcedure
      .input(z.object({
        initiativeId: z.string().min(1),
        phases: z.array(z.object({
          name: z.string().min(1),
        })),
      }))
      .mutation(async ({ ctx, input }) => {
        const repo = requirePhaseRepository(ctx);
        const created: Phase[] = [];
        for (const p of input.phases) {
          const phase = await repo.create({
            initiativeId: input.initiativeId,
            name: p.name,
            status: 'pending',
          });
          created.push(phase);
        }
        return created;
      }),

    listInitiativePhaseDependencies: publicProcedure
      .input(z.object({ initiativeId: z.string().min(1) }))
      .query(async ({ ctx, input }) => {
        const repo = requirePhaseRepository(ctx);
        return repo.findDependenciesByInitiativeId(input.initiativeId);
      }),

    createPhaseDependency: publicProcedure
      .input(z.object({
        phaseId: z.string().min(1),
        dependsOnPhaseId: z.string().min(1),
      }))
      .mutation(async ({ ctx, input }) => {
        const repo = requirePhaseRepository(ctx);

        const phase = await repo.findById(input.phaseId);
        if (!phase) {
          throw new TRPCError({
            code: 'NOT_FOUND',
            message: `Phase '${input.phaseId}' not found`,
          });
        }

        const dependsOnPhase = await repo.findById(input.dependsOnPhaseId);
        if (!dependsOnPhase) {
          throw new TRPCError({
            code: 'NOT_FOUND',
            message: `Phase '${input.dependsOnPhaseId}' not found`,
          });
        }

        await repo.createDependency(input.phaseId, input.dependsOnPhaseId);
        return { success: true };
      }),

    getPhaseDependencies: publicProcedure
      .input(z.object({ phaseId: z.string().min(1) }))
      .query(async ({ ctx, input }) => {
        const repo = requirePhaseRepository(ctx);
        const dependencies = await repo.getDependencies(input.phaseId);
        return { dependencies };
      }),

    getPhaseDependents: publicProcedure
      .input(z.object({ phaseId: z.string().min(1) }))
      .query(async ({ ctx, input }) => {
        const repo = requirePhaseRepository(ctx);
        const dependents = await repo.getDependents(input.phaseId);
        return { dependents };
      }),

    removePhaseDependency: publicProcedure
      .input(z.object({
        phaseId: z.string().min(1),
        dependsOnPhaseId: z.string().min(1),
      }))
      .mutation(async ({ ctx, input }) => {
        const repo = requirePhaseRepository(ctx);
        await repo.removeDependency(input.phaseId, input.dependsOnPhaseId);
        return { success: true };
      }),

    getPhaseReviewDiff: publicProcedure
      .input(z.object({ phaseId: z.string().min(1) }))
      .query(async ({ ctx, input }) => {
        const phaseRepo = requirePhaseRepository(ctx);
        const initiativeRepo = requireInitiativeRepository(ctx);
        const projectRepo = requireProjectRepository(ctx);
        const branchManager = requireBranchManager(ctx);

        const phase = await phaseRepo.findById(input.phaseId);
        if (!phase) {
          throw new TRPCError({ code: 'NOT_FOUND', message: `Phase '${input.phaseId}' not found` });
        }
        if (phase.status !== 'pending_review' && phase.status !== 'completed') {
          throw new TRPCError({ code: 'BAD_REQUEST', message: `Phase is not reviewable (status: ${phase.status})` });
        }

        const initiative = await initiativeRepo.findById(phase.initiativeId);
        if (!initiative?.branch) {
          throw new TRPCError({ code: 'BAD_REQUEST', message: 'Initiative has no branch configured' });
        }

        const initBranch = initiative.branch;
        const phBranch = phaseBranchName(initBranch, phase.name);
        const diffBase = (phase.status === 'completed' && phase.mergeBase) ? phase.mergeBase : initBranch;

        const projects = await projectRepo.findProjectsByInitiativeId(phase.initiativeId);

        if (projects.length === 0) {
          return {
            phaseName: phase.name,
            sourceBranch: phBranch,
            targetBranch: initBranch,
            files: [],
            totalAdditions: 0,
            totalDeletions: 0,
          };
        }

        const firstClone = await ensureProjectClone(projects[0], ctx.workspaceRoot!);
        const headHash = await branchManager.getHeadCommitHash(firstClone, phBranch);
        const cacheKey = `${input.phaseId}:${headHash}`;

        type PhaseReviewDiffResult = { phaseName: string; sourceBranch: string; targetBranch: string; files: FileStatEntry[]; totalAdditions: number; totalDeletions: number };
        const cached = phaseMetaCache.get(cacheKey) as PhaseReviewDiffResult | undefined;
        if (cached) return cached;

        const files: FileStatEntry[] = [];

        for (const project of projects) {
          const clonePath = await ensureProjectClone(project, ctx.workspaceRoot!);
          const entries = await branchManager.diffBranchesStat(clonePath, diffBase, phBranch);
          for (const entry of entries) {
            const tagged: FileStatEntry = { ...entry, projectId: project.id };
            if (projects.length > 1) {
              tagged.path = `${project.name}/${entry.path}`;
              if (entry.oldPath) {
                tagged.oldPath = `${project.name}/${entry.oldPath}`;
              }
            }
            files.push(tagged);
          }
        }

        const totalAdditions = files.reduce((sum, f) => sum + f.additions, 0);
        const totalDeletions = files.reduce((sum, f) => sum + f.deletions, 0);

        const result = {
          phaseName: phase.name,
          sourceBranch: phBranch,
          targetBranch: initBranch,
          files,
          totalAdditions,
          totalDeletions,
        };
        phaseMetaCache.set(cacheKey, result);
        return result;
      }),

    getFileDiff: publicProcedure
      .input(z.object({
        phaseId: z.string().min(1),
        filePath: z.string().min(1),
        projectId: z.string().optional(),
      }))
      .query(async ({ ctx, input }) => {
        const phaseRepo = requirePhaseRepository(ctx);
        const initiativeRepo = requireInitiativeRepository(ctx);
        const projectRepo = requireProjectRepository(ctx);
        const branchManager = requireBranchManager(ctx);

        const phase = await phaseRepo.findById(input.phaseId);
        if (!phase) {
          throw new TRPCError({ code: 'NOT_FOUND', message: `Phase '${input.phaseId}' not found` });
        }
        if (phase.status !== 'pending_review' && phase.status !== 'completed') {
          throw new TRPCError({ code: 'BAD_REQUEST', message: `Phase is not reviewable (status: ${phase.status})` });
        }

        const initiative = await initiativeRepo.findById(phase.initiativeId);
        if (!initiative?.branch) {
          throw new TRPCError({ code: 'BAD_REQUEST', message: 'Initiative has no branch configured' });
        }

        const initBranch = initiative.branch;
        const phBranch = phaseBranchName(initBranch, phase.name);
        const diffBase = (phase.status === 'completed' && phase.mergeBase) ? phase.mergeBase : initBranch;

        const decodedPath = decodeURIComponent(input.filePath);

        const projects = await projectRepo.findProjectsByInitiativeId(phase.initiativeId);

        const firstClone = await ensureProjectClone(projects[0], ctx.workspaceRoot!);
        const headHash = await branchManager.getHeadCommitHash(firstClone, phBranch);
        const cacheKey = `${input.phaseId}:${headHash}:${input.filePath}`;
        const cached = fileDiffCache.get(cacheKey);
        if (cached) return cached;

        let clonePath: string;
        if (input.projectId) {
          const project = projects.find((p) => p.id === input.projectId);
          if (!project) {
            throw new TRPCError({ code: 'NOT_FOUND', message: `Project '${input.projectId}' not found for this phase` });
          }
          clonePath = await ensureProjectClone(project, ctx.workspaceRoot!);
        } else {
          clonePath = firstClone;
        }

        const git = simpleGit(clonePath);
        // Binary files appear as "-\t-\t<path>" in --numstat output
        const numstatOut = await git.raw(['diff', '--numstat', `${diffBase}...${phBranch}`, '--', decodedPath]);
        if (numstatOut.trim() && numstatOut.startsWith('-\t-\t')) {
          const binaryResult = { binary: true, rawDiff: '' };
          fileDiffCache.set(cacheKey, binaryResult);
          return binaryResult;
        }

        const rawDiff = await branchManager.diffFileSingle(clonePath, diffBase, phBranch, decodedPath);
        const result = { binary: false, rawDiff };
        fileDiffCache.set(cacheKey, result);
        return result;
      }),

    approvePhaseReview: publicProcedure
      .input(z.object({ phaseId: z.string().min(1) }))
      .mutation(async ({ ctx, input }) => {
        const orchestrator = requireExecutionOrchestrator(ctx);
        await orchestrator.approveAndMergePhase(input.phaseId);
        return { success: true };
      }),

    getPhaseReviewCommits: publicProcedure
      .input(z.object({ phaseId: z.string().min(1) }))
      .query(async ({ ctx, input }) => {
        const phaseRepo = requirePhaseRepository(ctx);
        const initiativeRepo = requireInitiativeRepository(ctx);
        const projectRepo = requireProjectRepository(ctx);
        const branchManager = requireBranchManager(ctx);

        const phase = await phaseRepo.findById(input.phaseId);
        if (!phase) {
          throw new TRPCError({ code: 'NOT_FOUND', message: `Phase '${input.phaseId}' not found` });
        }
        if (phase.status !== 'pending_review' && phase.status !== 'completed') {
          throw new TRPCError({ code: 'BAD_REQUEST', message: `Phase is not reviewable (status: ${phase.status})` });
        }

        const initiative = await initiativeRepo.findById(phase.initiativeId);
        if (!initiative?.branch) {
          throw new TRPCError({ code: 'BAD_REQUEST', message: 'Initiative has no branch configured' });
        }

        const initBranch = initiative.branch;
        const phBranch = phaseBranchName(initBranch, phase.name);
        const diffBase = (phase.status === 'completed' && phase.mergeBase) ? phase.mergeBase : initBranch;
        const projects = await projectRepo.findProjectsByInitiativeId(phase.initiativeId);

        const allCommits: Array<{ hash: string; shortHash: string; message: string; author: string; date: string; filesChanged: number; insertions: number; deletions: number }> = [];

        for (const project of projects) {
          const clonePath = await ensureProjectClone(project, ctx.workspaceRoot!);
          const commits = await branchManager.listCommits(clonePath, diffBase, phBranch);
          allCommits.push(...commits);
        }

        return { commits: allCommits, sourceBranch: phBranch, targetBranch: initBranch };
      }),

    getCommitDiff: publicProcedure
      .input(z.object({ phaseId: z.string().min(1), commitHash: z.string().min(1) }))
      .query(async ({ ctx, input }) => {
        const phaseRepo = requirePhaseRepository(ctx);
        const projectRepo = requireProjectRepository(ctx);
        const branchManager = requireBranchManager(ctx);

        const phase = await phaseRepo.findById(input.phaseId);
        if (!phase) {
          throw new TRPCError({ code: 'NOT_FOUND', message: `Phase '${input.phaseId}' not found` });
        }

        const projects = await projectRepo.findProjectsByInitiativeId(phase.initiativeId);
        let rawDiff = '';

        for (const project of projects) {
          const clonePath = await ensureProjectClone(project, ctx.workspaceRoot!);
          try {
            const diff = await branchManager.diffCommit(clonePath, input.commitHash);
            if (diff) rawDiff += diff + '\n';
          } catch {
            // commit not in this project clone
          }
        }

        return { rawDiff };
      }),

    listReviewComments: publicProcedure
      .input(z.object({ phaseId: z.string().min(1) }))
      .query(async ({ ctx, input }) => {
        const repo = requireReviewCommentRepository(ctx);
        return repo.findByPhaseId(input.phaseId);
      }),

    createReviewComment: publicProcedure
      .input(z.object({
        phaseId: z.string().min(1),
        filePath: z.string().min(1),
        lineNumber: z.number().int(),
        lineType: z.enum(['added', 'removed', 'context']),
        body: z.string().min(1),
        author: z.string().optional(),
      }))
      .mutation(async ({ ctx, input }) => {
        const repo = requireReviewCommentRepository(ctx);
        return repo.create(input);
      }),

    updateReviewComment: publicProcedure
      .input(z.object({
        id: z.string().min(1),
        body: z.string().trim().min(1),
      }))
      .mutation(async ({ ctx, input }) => {
        const repo = requireReviewCommentRepository(ctx);
        const comment = await repo.update(input.id, input.body);
        if (!comment) {
          throw new TRPCError({ code: 'NOT_FOUND', message: `Review comment '${input.id}' not found` });
        }
        return comment;
      }),

    resolveReviewComment: publicProcedure
      .input(z.object({ id: z.string().min(1) }))
      .mutation(async ({ ctx, input }) => {
        const repo = requireReviewCommentRepository(ctx);
        const comment = await repo.resolve(input.id);
        if (!comment) {
          throw new TRPCError({ code: 'NOT_FOUND', message: `Review comment '${input.id}' not found` });
        }
        return comment;
      }),

    unresolveReviewComment: publicProcedure
      .input(z.object({ id: z.string().min(1) }))
      .mutation(async ({ ctx, input }) => {
        const repo = requireReviewCommentRepository(ctx);
        const comment = await repo.unresolve(input.id);
        if (!comment) {
          throw new TRPCError({ code: 'NOT_FOUND', message: `Review comment '${input.id}' not found` });
        }
        return comment;
      }),

    replyToReviewComment: publicProcedure
      .input(z.object({
        parentCommentId: z.string().min(1),
        body: z.string().trim().min(1),
        author: z.string().optional(),
      }))
      .mutation(async ({ ctx, input }) => {
        const repo = requireReviewCommentRepository(ctx);
        return repo.createReply(input.parentCommentId, input.body, input.author);
      }),

    requestPhaseChanges: publicProcedure
      .input(z.object({
        phaseId: z.string().min(1),
        summary: z.string().trim().min(1).optional(),
      }))
      .mutation(async ({ ctx, input }) => {
        const orchestrator = requireExecutionOrchestrator(ctx);
        const reviewCommentRepo = requireReviewCommentRepository(ctx);

        const allComments = await reviewCommentRepo.findByPhaseId(input.phaseId);
        // Build threaded structure: unresolved root comments with their replies
        const rootComments = allComments.filter((c) => !c.parentCommentId);
        const repliesByParent = new Map<string, typeof allComments>();
        for (const c of allComments) {
          if (c.parentCommentId) {
            const arr = repliesByParent.get(c.parentCommentId) ?? [];
            arr.push(c);
            repliesByParent.set(c.parentCommentId, arr);
          }
        }

        const unresolvedThreads = rootComments
          .filter((c) => !c.resolved)
          .map((c) => ({
            id: c.id,
            filePath: c.filePath,
            lineNumber: c.lineNumber,
            body: c.body,
            author: c.author,
            replies: (repliesByParent.get(c.id) ?? []).map((r) => ({
              id: r.id,
              body: r.body,
              author: r.author,
            })),
          }));

        if (unresolvedThreads.length === 0 && !input.summary) {
          throw new TRPCError({
            code: 'BAD_REQUEST',
            message: 'Add comments or a summary before requesting changes',
          });
        }

        const result = await orchestrator.requestChangesOnPhase(
          input.phaseId,
          unresolvedThreads,
          input.summary,
        );
        return { success: true, taskId: result.taskId };
      }),
  };
}